Pituitary tumors and subsequent treatment with endoscopic transsphenoidal surgery (ETSS) may cause injury to suprasellar structures, causing long-term
fatigue and neurocognitive impairment. A method to quantify
brain injury after ETSS is not available. In this prospective, exploratory study of patients undergoing ETSS for
pituitary tumors, a novel approach to detect possible neuronal damage is presented. Plasma concentrations of
brain injury biomarkers (
glial fibrillary acidic protein [GFAP], tau, and neurofilament light [NFL]) were measured the day before surgery, immediately after surgery, at day 1 and 5, and at 6 and 12 months after surgery, using
enzyme-linked
immunosorbent assays. The association between the increase of
biomarkers with preoperative
tumor extension and postoperative patient-perceived
fatigue was evaluated. Suprasellar
tumor extension was assessed from MRI scans, and self-perceived
fatigue was assessed using the Multidimensional
Fatigue Inventory before and 6 months after surgery. Thirty-five patients were included in the analysis. Compared to baseline, GFAP showed a maximal increase at day 1 after surgery (p = 0.0005), tau peaked postoperatively on the day of surgery (p = 0.019), and NFL reached its maximum at day 5 after surgery (p < 0.0001). The increase in GFAP correlated with preoperative chiasmal compression (p = 0.020). The increase in tau was correlated with preoperative chiasmal (p = 0.011) and hypothalamus compression (p = 0.016), and
fatigue score 6 months after surgery (p = 0.016). In conclusion, the concentrations of
brain injury biomarkers in blood increased after ETSS for
pituitary tumors. The results indicate that postoperative plasma GFAP and tau might reflect astroglial and neuronal damage after ETSS.